Decrease of velocity and acceleration of fast eye movement after the administration of methadone

Abstract

AimsThe goal of this study is to assess the differences in peak and medium velocity, peak and medium acceleration of eyeball movements after the administration of methadone.Materials and methodsTwenty-eight opioid addicts were examined. Patients admitted oculomotor impaired were excluded.In this study, we made use of the Saccadometer Advanced (Advanced Clinical Instrumentation, Cambridge, UK), allowing the measurement of eye position with the time resolution of 1 msec (1000 Hz). The eye movement measurement is automated and synchronised with stimuli presentation. Before and after the administration of methadone two saccadic tests were carried out: Prosaccades Test (PT) and Antisaccades Test (AT).ResultsThe average of peak and medium velocity and the average of peak and medium acceleration of eyeball movements in the test AT were lower than in the PT test. After administration of a single dose of methadone the peak and medium velocity, peak and medium acceleration decreased in both tests (PT and AT). After administration of methadone prolonged the duration of saccades, and prolonged the duration of rising and falling slope of saccades.ConclusionIt was found that methadone (μ-opioid receptor agonist) is associated with change of velocity and acceleration of eyeball movements.Disclosure of interestThe authors have not supplied their declaration of competing interest.